My wife drives a 2003 sedan. I liked the way it runs so much I bought a 2008 sedan. Both are A/T. I figured with the extra HP mine would be an even better experience. Hers is much more fun to drive as far as throttle response goes. I couldn't understand why. I searched the forums looking for a possible reason. The results I found said ALL G35's are drive by wire. I just took a look at our gas pedals. They look nothing alike. Mine is attached to the floor. Hers is attached to a rod that drops down from above. What does this all mean? Obviously I'm not a mechanic!

 

It's just different ways of attaching the pedal to the switch. No difference in power delivery.

You might check with Infiniti/Nissan to see if you have an ECM software update for the HR, also check your HR engine for any vacuum leaks that might be causing a bit of a delay in power delivery.

However the HR sedan weighs 300 lbs more than the previous V36 DE engine equipped one (if they're both RWD, not AWD), you might just be feeling that extra weight.

 

Both are RWD. You describe the difference perfectly. Mine feels as if it weighs a LOT more than hers. The pedal on the 2003 just feels much "lighter" on the foot. Surprised they're both DBW. Thought I had discovered the reason for the difference.